Drifting-valve.



C. JAMES.

DRIFTING VALVE.

APPLICATION FILED N0v.z5, 1913.

1,111,903. ratenwase uzalsm] wag-1:12;; gear WITNESSES v INVENTOR Ge /W45; 21455 ATTORNEYS UNITED STATES PATENT oriuon. A

CHARLES JAMss, or nurnnaronb, NEW JERSEY.

DRIETING-VALVE.

To all whom it may concern 1 Be it known that I, (JHARLESJAMES, a

citizen of the United States, and a resident of Rutherford, in' the county of Bergen and" State of New Jersey, have invented a new and Improved Drifting-Valve, of which the same is drifting, the supply being dimin-.

ished and determined as the progress of the locomotive diminishes and ceases; to provide means, operated mechanically in unison with the moving parts of the locomotive, for'controlling the supply of steamto the cylinders; and to provide a mechanism for attaining the above-stated objects, which is simple and efi'ective in construction and operation.

The drawing is a longitudinal section taken on, the median line of a valve and operating mechanism therefor, constructed and arranged in accordance with the present invention. v

The valve casing 5 maybe mounted in any convenient location to the mechanism in conjunction with which thevalve herein de scribed is operated. The prime considera tion involved is the disposition of the connecting rod 6, which unites operatively the crosshead of the valve stem of a locomotive and the rocker arm 7 of the present apparatus. ,The casing 5 is bored to form two, chambers of unequal diameter, the larger chamber 8 providing a cylinder for a floating piston 9, while the smaller chamber 10 is provided with a lining 11, bored and ported to receive a valve piston12.

The pistons 9. and 12 are rigidly connected by a stem 13, and are provided with packing rings 14: and 15,.respectively.

i The pistons 9 and 12 are of relatively different diameters, to expose different areas to steam delivered by a pipe 16 from the turret of the locomotive, to the chambers 10 and 8, and between said pistons. The superior area presented by the piston 9 re sults in moving the two pistons and connecting stem to the position shown in the drawings, where the piston 9 rests against the head 17 of the casing 5. The head 17. is centrally bossed to arrest the piston. 9 in Specification of Letters Patent.

- position to form a space 18 between the head 17 and said piston, to clear the ends of passages 19,20 and-21.. The passage 19 is I Patented Sept. 29, 1914'. App1ication filed November as, 1913. seri l No. 802,903. p

exposed to the surrounding atmospherev to,

permit the air behind the piston 9 to escape therefrom and avoid cushioning said piston.

In theposition of the piston9 above described, the piston 12 rests between the port 22 with which the pipe 16 is connected and ports 23 opening through the lining 11 to an annular chamber 24:, which is in turn connected with a pipe 25. The pipe 25 is in direct communication with the steam-chest v of one or more of the cylinders of the locomotive.

When the piston 12 is held in the position I shown in the drawings, it is obvious that the steam entering from the pipe 16 does not flow through the ports 23 and pipe 25.

As long as the throttle is open to supply steam to the steam-chest of the cylinders, the over-balance of the pressure of steam in the chamber 10'exerted on the piston 9 retains the combined pistons 9 and 12 in the position shown in the drawings. When, however, the power steam is cut oil, the

pistons 9 and 12 are moved by the pressure' of air in the space 18, backward until the piston 12 rests upon a boss 26 formed of a head 27, which closes the end of the casing 5. The air pressure, as hereinafter explained, lessens and finally determines with the suspension of movement of the locomotive. When the air pressure is thus deter: mined in the space 18, the overbalance of the pressure of the steam supplied to the chamber 10 from the pipe 16 exerted on, the piston 9 moves the combined pistons 9 and 12 to the position shown in the drawings, In this position, the relatively low-pressure steam in the chamber 10 is prevented from passing to the power cylinders of the locomotive, with the possibleconsequence of building up in said cylinders sufficient pressure to move the same-and cause the loco motive to creep.

The air pressure in the space 18 is produced by operation of the plunger having the piston 28. The piston 28 is reciprocatively mounted in a cylinder 29 rigidly or integrally formed on the head 17 of the casing 5.- The space 18 at the end of the chamber 8 is held. in communication with the compression end of the cylinder 29 through the passage 201 when a valve 30 lifts.

- permit the aircompressed in the forward end thereof to escape through the passage to the space 18 .of the chamber 8. Air is drawn into the cylinder 29 when an intake valve 32 lifts, a passage being formed in a nut-head 33 to supply said cylinder 29.

The piston. 28 is rigidly mounted on a piston rod 34, the outer end whereof is slidably mounted in a bearing formed in a bracket 35 of a yoke 36. The piston rod 34 is provided with pins 37 extending from both sides of said rod through bearings 38 formed in the rockerarm 7. The rocker arm 7 is provided at the lower end with an elongated slot 39 to engage pins 40 extending from both sides of the yoke 36. It is upon thepins 40 that the arm 7 fulcrums,

the slot 39 permitting'the relative adjustment of said arm to the pins 40. necessary tomaintain the straight-line thrust of the 'rojd'34. As above stated, the rocker arm 7 'is preferably operated from the valve-stem cross-head, the stroke whereof is relatively slow andshort. It will be understood that by varying the relative length of the upper and lower extensions of the arm 7, the stroke of the piston 28 may be varied.

The pressure of air in the space 18 of the chamber 8is at all times maintained by a relief valve 41. The valve 41 is held seated by aspring 42, the tension whereof is varied b a follower nut 43, which is locked in position-by a'lock-nut 44. The nut 43 is held in a valve casing 45, which is supplied with side openings 46 to permit the escape of air from under the valve 41 through the passage 21, from the space 18 whenever the pressurein said space overbalances the pressure on'thevvalve 41 exerted by the spring 42.

Thepres'sure normally maintained in the space 18 is greater than the overbalance of the respective pressures of steam upon the pistons 9 and 12. The air in the space 18 is normally prevented from moving the pistons 9 and 12 by the steam delivered into the lower end of the chamber 10 on the far side of the piston 12 by the pipe 25. It will be understood that as the pressure of air produced by the piston 28 depends upon the movement of said piston, and the move ment of said piston depends upon the movement of the locomotive, the steam admitted to the power cylinders of the locomotiveenters the lower end of the chamber 10 in the chamber 5 before the air pressure in the space 18 is built up toits norma In this condition, it will be seen the pistons 9 and 12 are maintained in the position shown in the drawings by the united effect of the overbalance of steam from the pipe 16 and the direct pressure of steam from the pipe 25. It is after the pressure of steam in the pipe 25 determines, that the pressure of air in the cylinder 29 and space 18 operates to move the pistons 9 and 12 to expose the ports 23.

When, in the course of operation, the running speed of the locomotive diminishes or ceases, the operation of the piston 28 likewise slows or ceases, and the pressure of air behind the piston 9 diminishes and vanishes. When the pressure of air behind the piston 9 falls below the overbalance of pressure exerted by the steam from the pipe 16 on the piston 9, as compared-with the ressure exerted by it upon the piston 12, t e combined pistons are moved toward the opposite end of the casing 5, first covering the ports 23, and finally resting between the ports 22 and 23 in the position shown in the drawings.

The passa es 19 and 46 are small passa es to prevent t e trapping of air or steam ehind the pistons 9 and 12 when moved toward the respectively adjacent ends of the casing 5.

Claims.

1. In combination with a locomotive having power cylinders, .a power source, and

running gear; a valve comprising a casing having inlet and outlet ports; a valve plston movable in said casing to cover said outlet 4 port; a floatin piston operatively conconected with said valve piston; means operatively connecting said power source and (piston to move said valve piston to close sai outlet port; an air-pressure mechanism operatively connected with said floating piston to move the same in opposition to saidpower source; and a relief valve for said air-pressure mechanlsm, to regulate the maximum pressure thereof.

2. In combination with a locomotive having power cylinders, a power source, and running ear; a valve comprisin a casing having in at and outlet ports; a. v ve piston movable in said casing to cover-{said outlet port; a floating piston operatively connected with said valve piston; means operatively connecting said power source and floating piston to move said valve piston to close said outlet port; and an. air-pump operatively connected With said running gear, arranged to deliver into said casing, at the far side of said floating piston, to move the same in opposition to the pressure of said power source.

3. In combination with a locomotive having power cylinders, a power source, and running gear; a valve comprising a cylindrical casing interposed between said power source and power cylinders, said casin having longitudinally separated inlet an outlet ports; a valve piston to expose and close said outlet port; a floating piston of relatively larger diameter operatively mounted in said casing; a piston rod connecting said pistons, said rod being arranged to maintain said pistons continuously at opposite sides of said inlet port; an air-compression pump operatively connecting said casing, to deliver air under pressure be tween said floating piston and the adjacent port opposite that where said valve piston rests, to secure angunbalanced pressure loc tween said pistons; a piston rod rigidly connecting said pistons; an air pump operatively connected With said running gear to deliver air under pressure at the far side of said fioating'piston; and a relief valve opening from said casing to operate at a pressure greater than the said unbalanced pressure exerted on said pistons.

In testimony whereof I have signed my name to thisspecification in the presence 30 of two subscribing witnesses.

CHARLES JAMES.

Witnesses:

L. R. GLASS, DENNIS A. ODRIscoLL. 

